In FPM (Fourier ptychographic microscopy) system, an ordinary microscope light source is replaced by a programmable LED array, thus introducing illuminating with multiple angles of coherent lights into the conventional microscopy system, and realizing imaging with wide field of view and high resolution. In data collection process, LED light sources with different incident angles are lit up sequentially, and a plurality of low-resolution images of a sample illuminated by a corresponding light is simultaneously collected. Each collected low resolution image contains information of the sample illuminated by different angle of light, that is, it contains different frequency spectrum information of the sample. Therefore, a phase retrieval algorithm may be used to stitch information contained in these images on a spatial frequency domain (namely Fourier domain), to obtain a complex amplitude image with a high resolution of the sample (namely an intensity image and a phase image of the sample). With the FPM method, images of one billion pixels of the sample can be obtained without mechanical scanning, greatly broadening spatial bandwidth product (SBP for short) of a microscope objective lens, thus increasing optical information throughput of the microscopy system.
However, one limitation of the FPM method is that the data collection process takes a long time. To some extent, the FPM method can be regarded as a method that obtains high spatial resolution by sacrificing temporal resolution. A prototype system of the FPM method uses the above sequential illumination strategy, in which several minutes may be taken to collect more than 200 original low-resolution images, so as to restore the complex amplitude image with high resolution of the sample. This limitation makes dynamic activity of the sample unable to be observed with the FPM system, which limits application in biological imaging of the FPM system.